What's so great about using a mini - ITX board?

I don't mean to sound ignorant, of course I realize some of the advantages. However, some of the disadvantages are bringing me down, namely the fact that you can only add one, mabe two PCI cards. I'm just wondering what everyone would site as the major disadvantages of simply putting a shuttle in the trunk.

I don't mean to sound ignorant, of course I realize some of the advantages. However, some of the disadvantages are bringing me down, namely the fact that you can only add one, mabe two PCI cards. I'm just wondering what everyone would site as the major disadvantages of simply putting a shuttle in the trunk.

The Shuttle can't be integrated as "cleanly" as a custom miniITX install. It's a cube, whereas some miniITX cases are fairly low profile and can be concealed easily.

And then there's also the power requirements. As long as the board and CPU in a Shuttle can operate with 90-150w, it might be easy enough to power with an Opus or M1-atx. Otherwise you have to look to other PSU options (read: more powerful).

Some people don't have trunks, I don't. Moreover, I don't have a Mini-ITX system.

It's preference, weigh it for yourself. Forget about what others say about advantage/disadvantage, it's your system and you're going to have to deal with it, no one else most likely.

Mini-ITX built with elements and resource utilization in mind not so much expansion and Micro-ATX built with some expansion not so much element defense or care of resource issues. It's always a trade off.